Sub frame woes

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The Skunk

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Been inactive for a long time (long story).. but I’m running into a set back on the car.

I have a 1972 2 dr dart swinger that I’m replacing the front subframe. I drilled the spot welds out of my donor 1972 4 door. Braced the front subframe and had it media blasted and epoxy primed. Turned out great.

so I removed my front subframe from my car by drilling the spot welds out as well. Patched the floor pan and am in the process of lining up my new subframe. Which has gone smoother then I originally though it would. But my measurements arnt matching Chrysler’s and I’m having a hard time pinpointing the exact measurement points on the chassis. Can anyone give me a crash course for dummies on this so I can see where or why my numbers don’t make sense?

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Man, that’s a loaded request without much information. Let’s start with, (why are you replacing the front clip?) AND, it’s not called a “subframe”. :)
 
Your rails obviously only have x amount of play against the crossmember. The inner fender has a hole in it at the top that lines up with a hole on the cowl. @Oldmanmopar (Steve)pointed this out in a post a while back. This hole is a designated point for installing. I’ll see if I can find that post again.

Ma’s tolerances were quite tolerant!
 
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Awesome. I’ll try that method and see what my measurements are at. I thought I read somewhere that mopar had up to 1/4” of tolerance but am trying to make sure I install everything straight. I even have the torsion bars in to help try and bring everything into position. But don’t want the car to dog walk going down the road lol.
 
And the reason to replacing the front clip was due to excessive frame rail rot on my original car. Most ppl would of used my car as a parts car but it’s my highschool car and the sentimental value far exceeds common sense. Thus the installation of the donor clip.
 
And the reason to replacing the front clip was due to excessive frame rail rot on my original car. Most ppl would of used my car as a parts car but it’s my highschool car and the sentimental value far exceeds common sense. Thus the installation of the donor clip.
Okay. I was worried that it had sustained damage and that that could be your issue. Like what has already been offered, you can kinda throw all of those measurements out the window and use the sheetmetal for the final answer.
 
I have a 1972 2 dr dart swinger that I’m replacing the front subframe
Be sure to excessively document the hidden chassis numbers on the radiator support of both cars. And that you have legally purchased the doner car. When all is said and done the vin on the car and the hidden numbers will no longer match.
 
I think you would have found it easier to disassemble everything from the tub and frame rails first, but we all do it differently, I guess.
 
Did you check your print measurements to both cars before you cut them apart? Kind of hard to understand what measurements are the ones you’re having trouble with without you sketching up what you have now.
 
I did this once....

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I was over-thinking it too. A guy on FBBO told me something that sticks with me:
Get the stub-frame in place with a few self tapping screws then start fitting the sheet metal.....
 
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Loosely set the fenders and hood and see how the gaps look.

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The hood to cowl gap was tested using paint mixing sticks that measure just shy of 1/4".

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The right fender to door is a little tighter than 1/4".

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If you are able to get the gaps even like you see in the last picture, you can start plug welding the fender aprons to the firewall, the frame rails to the torsion bar crossmember, etc.
The fender to hood gaps will tell you if the front end is square.

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In short, the man told me that if the sheet metal fits, the factory diagrams don't matter.
I rebuilt the engine and front suspension but have not had it aligned. I set the UCA cams as follows: Rear cam adjusted all the way IN, front cam all the way OUT. I'm either lucky or good because the car tracks straight, doesn't pull when braking, no tire squeal or irregular wear....

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In short, the man told me that if the sheet metal fits, the factory diagrams don't matter.
I rebuilt the engine and front suspension but have not had it aligned. I set the UCA cams as follows: Rear cam adjusted all the way IN, front cam all the way OUT. I'm either lucky or good because the car tracks straight, doesn't pull when braking, no tire squeal or irregular wear....

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Good job! It wants to live!
 
Thanks guys and I’m documenting the cars I do own both cars (titles in my name) and not being shy about it.

Also when you guys are using the fenders and hood to mock the subframe in are you bolting the fenders on completely putting the hood on the hinges? Or just laying the hood on? Also do I need to set my door gaps before hand? I hate to sound clueless but I’m notorious for over thinking and over analyzing. Being a son of engineer has its pitfalls lol. Thanks again
 
Thanks guys and I’m documenting the cars I do own both cars (titles in my name) and not being shy about it.

Also when you guys are using the fenders and hood to mock the subframe in are you bolting the fenders on completely putting the hood on the hinges? Or just laying the hood on? Also do I need to set my door gaps before hand? I hate to sound clueless but I’m notorious for over thinking and over analyzing. Being a son of engineer has its pitfalls lol. Thanks again
Yes. Door to 1/4 first, hood bolted on square to the cowl panel. EDIT: Another thing some people don’t realize is how height can affect length and width
Measurements. When you move some thing up or down on one end it moves in an arc.
 
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Thanks guys and I’m documenting the cars I do own both cars (titles in my name) and not being shy about it.

Also when you guys are using the fenders and hood to mock the subframe in are you bolting the fenders on completely putting the hood on the hinges? Or just laying the hood on? Also do I need to set my door gaps before hand? I hate to sound clueless but I’m notorious for over thinking and over analyzing. Being a son of engineer has its pitfalls lol. Thanks again
The hood and fenders can be installed with just a couple or three loose bolts to keep them from falling off.
My routine is to set the door to quarter panel gap which is technically not adjustable, or at least not easily adjusted due to the way the hinges are attached to the car. You can often close the gap with shims between the hinge and door but if the gap is too small, that means the hinges need to move forward. I've never had to do that yet.
 
Thanks guys. I finally got an opportunity to get back out in the garage tonight. Spent all night trying to get the driver door gap as even as possible.. holy cow that was a lengthy and colorful conversation to talk it into place and not as tight of a gap as I was expecting!

Hopefully tomorrow afternoon I’ll get the passenger side door adjusted and be ready to use the fenders and hood to line everything up. Thanks again guys I’ll try to document with some pictures as well
 
So finally after getting a wiggle here and a wiggle there. its in and came out better then I thought it would. I wanna thank you guys for sharing your experience and tips.

I let the body lines tell me what it wanted and it may not be perfect but it wasn’t in 72 let alone 2022 lol. all doors shut effortlessly and panel gaps are happy and even.
I will be sure to post more pictures in the daylight.

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